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| author |   Matti Vaittinen <mazziesaccount@gmail.com> | 2022-10-03 11:11:33 +0300 |
|---|---|---|
| committer |   Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2022-10-17 08:51:26 +0100 |
| commit | 54246b9034da08087ceb2083478c0d13403e12b4 (patch) | |
| tree | e00a5ba5f98038ea5c74a624e91f38a35f90a9d5 | |
| parent | iio: temperature: ltc2983: allocate iio channels once (diff) | |
| download | linux-dev-54246b9034da08087ceb2083478c0d13403e12b4.tar.xz linux-dev-54246b9034da08087ceb2083478c0d13403e12b4.zip | |
iio: at91-sama5d2_adc: Fix unsafe buffer attributes
The iio_triggered_buffer_setup_ext() was changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().
The added attribute "wrapping" does not copy the pointer to stored
string constant and when the sysfs file is read the kernel will access
to invalid location.
Change the IIO_CONST_ATTRs from the driver to IIO_DEVICE_ATTR in order
to prevent the invalid memory access.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/be69775aa302159f088b8b91894e6ec449bca65b.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 4294d6539cdb..33e251552214 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -2193,17 +2193,30 @@ static ssize_t at91_adc_get_watermark(struct device *dev, return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark); } +static ssize_t hwfifo_watermark_min_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", "2"); +} + +static ssize_t hwfifo_watermark_max_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", AT91_HWFIFO_MAX_SIZE_STR); +} + static IIO_DEVICE_ATTR(hwfifo_enabled, 0444, at91_adc_get_fifo_state, NULL, 0); static IIO_DEVICE_ATTR(hwfifo_watermark, 0444, at91_adc_get_watermark, NULL, 0); - -static IIO_CONST_ATTR(hwfifo_watermark_min, "2"); -static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR); +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0); +static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0); static const struct attribute *at91_adc_fifo_attributes[] = { - &iio_const_attr_hwfifo_watermark_min.dev_attr.attr, - &iio_const_attr_hwfifo_watermark_max.dev_attr.attr, + &iio_dev_attr_hwfifo_watermark_min.dev_attr.attr, + &iio_dev_attr_hwfifo_watermark_max.dev_attr.attr, &iio_dev_attr_hwfifo_watermark.dev_attr.attr, &iio_dev_attr_hwfifo_enabled.dev_attr.attr, NULL, |